Impact of the COVID-19 pandemic on COPD exacerbations in Japanese patients: a retrospective study

Various infection control measures implemented during the coronavirus disease (COVID-19) pandemic have reduced the number of respiratory infections, which are the most common cause of chronic obstructive pulmonary disease (COPD) exacerbations. Here, we investigated whether infectious disease prevention during the COVID-19 pandemic reduced COPD exacerbations and the characteristics of patients exhibiting exacerbations before and during the COVID-19 pandemic. We included outpatients and inpatients with moderate or severe COPD exacerbations who required systemic steroids between April 1, 2018 and March 31, 2022. Their medical records were retrospectively compared and analyzed in 2-year intervals (before and during the COVID-19 pandemic). During the 4-year observation period, 70,847 outpatients and 2,772 inpatients were enrolled; 55 COPD exacerbations were recorded. The number of COPD exacerbations decreased from 36 before to 19 during the COVID-19 pandemic. Regarding the characteristics of patients with exacerbations, the % forced expiratory volume in one second (52.3% vs. 38.6%, P = 0.0224) and body mass index (BMI) (22.5 vs. 19.3, P = 0.0127) were significantly lower during the COVID-19 pandemic than before the pandemic. The number of COPD exacerbations during the pandemic decreased. Additionally, the tendency for a reduction in COPD exacerbation was greatest in patients with preserved lung function or above-standard BMI patients.